McLaughlin had spun through the grass exiting the pit lane as he pushed on his new, alternate-compound Firestone tyres, briefly entering the track at the apex, which caused Power to run up the track to avoid him through Turn 2.
The two-time IndyCar champion hit the wall and spun back across the track and into the path of Chip Ganassi Racing’s Marcus Ericsson, who piled into Power and wrecked both cars.
It is the first time that IndyCar has used the softer tyres on an oval, and the practice session topped by Penske's Josef Newgarden was the only opportunity for teams to evaluate the rubber before the race as their use is banned in qualifying.
McLaughlin held his hands up to causing the accident, but not before Power had branded him a “dumbarse” on TV.
“It was my own fault,” McLaughlin told NBC Peacock. “Massive apologies to Marcus and the #8 crew and the #12 crew of Will.
“I was pushing the out lap on my brand-new set of red tyres and I cut the inside just a little bit coming off the apron and it must still be a little bit wet or something [after earlier rain delayed the session].
“It was very scary. I heard my spotter saying ‘car coming into [Turn] 1’ so I just tried to lock it down as best I could.
“I hate to see what happened, especially to a team-mate but not only that to competitors, and it was a really dangerous situation, but you try and look for every little bit on in- and out-laps and I didn’t see that it was damp, maybe because it was a little bit dark, and that’s no excuse but I was just trying to find that little bit.
“Two others paid for it and I feel terrible to be honest.”
Source: Autosport